1. Technical Field
The present invention relates to a liquid crystal display device in which a first mode displaying a first image and a second image which are divided based on the time the images are captured based on the time the images are captured or optically in an image display area, and a second mode displaying an image without dividing the image based on the time the image is captured or optically in the image display area are executed, and an electronic apparatus including the liquid crystal display device.
2. Related Art
A liquid crystal display device includes a liquid crystal panel having an image display area, and a backlight unit which supplies illumination light to the liquid crystal panel, and the backlight unit includes a light guiding plate which is overlappingly arranged at a side opposite to an output side of display light with respect to the liquid crystal panel, a light source which is arranged at the side surface of the light guiding plate, and a light source driving unit which drives the light source. In recent years, as a liquid crystal display device, a device in which a first mode displaying a first image and a second image which are divided based on the time the images are captured or optically in an image display area, and a second mode displaying an image without dividing thereof based on the time the image is captured or optically in the entire region of the image display area are executed has been proposed. For example, a liquid crystal display device in which a 3D mode (first mode) which displays a 3D image (three-dimensional image/stereoscopic image) using the first and second images, by displaying the first and second images by dividing thereof based on the time the images are captured or optically in an image display area, and a 2D mode (second mode) which displays a 2D image (two-dimensional image/planar image) without dividing the image based on the time the images are captured or optically in the entire image display area are used in a switching manner has been proposed. However, when the 3D image and the 2D image are displayed on the liquid crystal panel, as described below with reference to FIGS. 10A to 10C, a display of the 3D image becomes dark.
FIGS. 10A, 10B, and 10C are explanatory diagrams displaying a 3D image and a 2D image on a liquid crystal panel, and in which FIG. 10A is an explanatory diagram which illustrates an ON state of a light source, FIG. 10B is an explanatory diagram which illustrates an ON time period of the light source when displaying the 3D image, and FIG. 10C is an explanatory diagram which illustrates an ON time period of the light source when displaying the 2D image, respectively. In addition, in the examples illustrated in FIGS. 10A, 10B, and 10C, in the case of displaying either the 3D image, or the 2D image, as illustrated in light beams Ba, Bb, Bc, and Bd which are the light beams from the light source, and are denoted by arrows in FIG. 10A, it is assumed that light from the light source (not shown) are input from four side surfaces of a light guiding plate in a backlight unit.
First, as illustrated in FIG. 10B, when displaying the 3D image on the liquid crystal panel, a time t0 to t1 is a transitional period in which a left eye image (L) which has been displayed up to that point is rewritten as a right eye image (R) from the upper side to the lower side of the liquid crystal panel, and all of the light sources turn to OFF states during the transitional period. In the time t0 to t1, when rewriting from the left eye image (L) to the right eye image (R) is ended, the right eye image (R) is written in the liquid crystal panel again in the subsequent time t1 to t2. Since all of the light sources turn to ON state in the time t1 to t2, the right eye image (R) is displayed by the light beams Ba, Bb, Bc, and Bd from the light source. A viewer wears shutter glasses on which liquid crystal shutters corresponding to the left and right eyes are arranged, the right eye image (R) is displayed in the entire image display area, a liquid crystal shutter corresponding to the right eye of the shutter glasses becomes a transmission state in the time t1 to t2 in which all of the light sources are ON states, and the liquid crystal shutter corresponding to the left eye becomes a light shielding state. In this manner, the right eye image (R) is viewed only in the right eye. Hereinafter, similar operations are repeated. In contrast to this, when the 2D image is displayed on the liquid crystal panel, since all of the light sources are always ON states, an image is displayed by the light beams Ba, Bb, Bc, and Bd from the light source. Here, the ON state of the backlight unit is intermittent in the 3D mode, however, the ON state of the backlight unit in the 2D mode is continuous. For this reason, when the 3D image is displayed, there is a big difference in brightness between the 3D image and 2D image, since a light amount supplied to the liquid crystal panel from the backlight unit becomes a half of that when displaying the 2D image when displaying the 3D image. In addition, since the left eye image (L) and the right eye image (R) are displayed on the liquid crystal panel using a time difference, when the left eye image (L) and the right eye image (R) are composited, brightness of the 3D image is lowered by a half or less compared to that of the 2D image.
Therefore, a technology in which all of a plurality of light emitting elements which are arranged along one side surface of a light guiding plate as light sources are turned on when displaying a 3D image, and on the other hand, a plurality of light emitting elements are alternately turned on when displaying a 2D image has been proposed (refer to FIG. 2 in JP-A-2006-228723).
However, as in the technology which is disclosed in FIG. 2 in JP-A-2006-228723, in a technology in which a plurality of light emitting elements are alternately turned on when displaying a 2D image, since a light emitting element in an OFF state is interposed between light emitting elements which are ON states, a distribution of an intensity of light input to a light guiding plate becomes largely different in places, and as a result, there is a problem in that the distribution of an intensity of light input from the light guiding plate to a liquid crystal panel deteriorates, and an image quality remarkably deteriorates.
The above described problem similarly occurs when the first image and the second image are optically divided, and are displayed at the same time in an image display area using different polarization in a first mode, and a 3D image is displayed by the first and second images. In addition, the above problem similarly occurs when the first image formed by the 2D image which is displayed in the image display area is viewed by a specific person in the first mode, and the second image formed by the 2D image which is displayed in the image display area is viewed by a different person.